The role of lateral exchange in modulating the seaward flux of C, N, P.

构成地球上生命的所有生物都是由元素周期表中丰富的元素组成的，包括微量金属。然而，除了氧(O)和氢(H)之外，水的三个最重要的成分是碳(C)、氮(N)和磷(P)。这些都被称为宏观营养素。这些常量营养素在生物(微生物、植物、动物、我们)和环境(大气、土地、河流、海洋)之间不断循环。在人类干预之前(大约在工业革命后，二战以来更是如此)，这些“循环”基本上是平衡的：植物吸收二氧化碳并产生O2，为了做到这一点，从环境(土壤、河流)中吸收有限数量的N和P，在死亡时，这些“隔离”的C、N、P返回地球。问题是，人类或人为活动已经使这些关键的宏观营养循环失去了平衡。例如，在恐龙时代之前从大气中提取的大量曾经是化石的碳，正在我们的发电站中燃烧，这在最近一段时间使大气中的二氧化碳增加了约30%。也许更令人担忧的是，人类的工业努力使可用于给植物施肥的氮素增加了一倍多，大量的磷也通过化肥和污水释放出来。随着人口的持续增长，发展中世界正在赶超西方世界，宏观营养循环中的这些失衡势必加剧。事实上，人类活动对地球的影响如此之大，以至于有人将其称为“人类世”：地质学的新纪元。与这些失衡相关的环境和社会问题是多样和复杂的；大多数人会熟悉全球变暖和二氧化碳背后的概念，但很少有人会意识到与甲烷和一氧化二氮的联系，或者我们饮用水中过量硝酸盐的潜在健康影响。这些失衡并未被忽视，事实上，已经花费了大量的科学、政策和管理来缓解这些失衡的影响。然而，尽管我们在过去30-40年左右的时间里在支持这一理解的科学方面取得了进展，但太多的科学研究集中在个体的宏观营养物质上，如N，以及在地貌的孤立部分，如河流。更复杂的是，这种知识和理解通常是通过不同的、有时甚至是过时的技术来获得的。人类活动将这种大规模的营养物质污染扩散到了整个景观。其中一些被生命吸收，一些被储存，但有相当大一部分通过地貌流向我们已经受到威胁的海洋。我们需要了解常量营养素在景观的不同部分移动或流动时会发生什么，而这种理解只有通过一个真正的综合科学计划才能实现，该计划同时研究常量营养素在景观不同部分的命运。在这里，我们将首次使用真正最先进的技术，对陆地上和土地排水的河流中所有三种常量营养素的循环和流动进行平行测量，最重要的是，将宏观养分从陆地输送到河流的水的流动，例如水文学。此外，我们将在不同的农业用途下，比较不同类型的土地和河流上的这些平行测量数据：粘土、砂岩和白垩岩，以了解土地上的自行车是如何通过水的运动与河流中的自行车联系起来的。

All living organisms that make up life on Earth are made from a profusion of elements in the periodic table, including trace metals. However, in addition to oxygen (O) and hydrogen (H), the constituents of water, the three most important are Carbon (C), Nitrogen (N) and Phosphorus (P). These have become known as the Macro-Nutrients. These macronutrients are in constant circulation between living organisms (microbes, plants, animals, us) and the environment (atmosphere, land, rivers, oceans). Until human intervention (circa post industrial revolution and even more so since WWII) these 'cycles' were largely in balance: plants took up CO2 and produced O2 and, in order to do so, took up limited amounts of N and P from the environment (soils, rivers) and, on death, this "sequestered" C,N,P was returned back to the Earth. The problem is that human or anthropogenic activity has put these key macro-nutrient cycles out of balance. For example, vast quantities of once fossilised carbon, taken out of the atmosphere before the age of the dinosaurs, are being burnt in our power stations and this has increased atmospheric CO2 by about 30 % in recent times. More alarmingly, perhaps, is that man's industrial efforts have more than doubled the amount of N available to fertilize plants, and vast amounts of P are also released through fertilizer applications and via sewage. As the population continues to grow, and the developing world catches up, and most likely overtakes, the western world, these imbalances in the macro-nutrient cycles are set to be exacerbated. Indeed, such is the impact of man's activity on Earth that some are calling this the 'Anthropocene': Geology's new age. The environmental and social problems associated with these imbalances are diverse and complex; most people would be familiar with the ideas behind global warming and CO2 but fewer may appreciate the links to methane and nitrous oxide or the potential health impacts of excess nitrate in our drinking water. These imbalances are not being ignored and indeed a great deal of science, policy and management has been expended to mitigate the impacts of these imbalances. However, despite our progress in the science underpinning this understanding over the last 30-40 years or so, too much of this science has been focused on the individual macro-nutrients e.g. N, and in isolated parts of the landscape e.g. rivers. To compound this even further, such knowledge and understanding has often been garnered using disparate, or sometimes even antiquated, techniques. Anthropogenic activity has spread this macro-nutrient pollution all over the landscape. Some of it is taken up by life, some is stored, but a good deal of it works its way through the landscape towards our already threatened seas. We need to understand what happens to the macronutrients as they move, or flux, through different parts of the landscape and such understanding can only come about by a truly integrated science programme which examines the fate of the macronutrients simultaneously in different parts of the landscape. Here we will for the first time make parallel measurements, using truly state-of-the-art technologies, of the cycling and flux of all three macronutrients on the land and in the rivers that that land drains and, most importantly, the movement of water that transports the macro-nutrients from the land to the rivers e.g. the hydrology. Moreover, we will compare these parallel measurements across land to river in different types of landscapes: clay, sandstone and chalk, subjected to different agricultural usage in order to understand how the cycling on the land is connected, via the movement of water, to that in the rivers.